Convert Sequelize model to JSON Schema for user input validation - node.js

Question

Planning to use AJV
for validating user inputs. AJV needs data model JSON Schema to validate user inputs. So, we need to derive JSON Schema from Sequelize model. Is there a way to get JSON schema from Sequelize model programatically?

Answer 1

A late answer, but I ended up creating sequelize-to-json-schema to solve this for our needs.
It offers more customisation in terms of which attributes you include in your schema and adding virtual attributes that might be used by your create method or similar.
Example
// assuming you have a user model with the properties
// name (string) and status (enum: real, imagined)
const schemaFactory = require('sequelize-to-json-schema');
const factory = new SchemaFactory({
customSchema: {
user: {
name: { description: "The user's name" },
status: { description: 'Was it all just a dream?' },
},
}
hrefBase: 'http://schema.example',
});
const schemaGenerator = factory.getSchemaGenerator(User);
const schema = schemaGenerator.getSchema();
// Results in
schema = {
{
title: 'User',
'$id': 'http://schema.example/user.json',
type: 'object',
'$schema': 'http://json-schema.org/draft-06/schema#',
properties: {
name: {
'$id': '/properties/fullname',
type: 'string',
examples: [],
title: 'Name',
description: "The user's name",
},
status: {
'$id': '/properties/status',
type: 'string',
examples: ['REAL', 'IMAGINED'],
enum: ['REAL', 'IMAGINED'],
title: 'Status',
description: 'Was it all just a dream?'
}
}
}
}
Note: sequelize-to-json-schema generates draft-06 schemas, to use that with AJV, their README says you'll need to do:
ajv.addMetaSchema(require('ajv/lib/refs/json-schema-draft-06.json'));